1. Field of the Invention
The present invention relates to a method of drying a coating film formed on a PET film surface and a coating film drying furnace.
2. Description of Related Art
In a process of manufacturing an electronic component having a multiple-layer structure, such as an MLCC (multiple-layer ceramic capacitor), a chip inductor, or an LTCC (low-temperature co-fired ceramic), a technique of forming a coating film containing a ceramic powder or metal powder, an organic binder, and an organic solvent on a surface of a base film, peeling the coating film off from the base film after drying the film, and stacking the film is adopted, as shown, for example, in JP 07-251411 A. As this base film, a PET film being excellent in strength and inexpensive is widely used.
In order to enhance the productivity of this drying step, an infrared heater or a warm air is generally used as heating means. However, by such a conventional method, the base film that has been expanded by being heated during the drying shrinks in the cooling step after the drying, whereby a compression stress is generated in the coating film formed on the surface thereof. The coating film that has received the compression stress is deformed when peeled off from the base film, thereby causing a problem of decrease in dimension precision in the stacking step. Also, when the drying temperature is lowered in order to avoid this problem, it will take a long period of time until the drying is completed, thereby leading to decrease in productivity.